Most AVs and Firewalls don't recognise PuPs as threats so it doesn't matter which program you use, although some AV programs are starting to incorporate that, but it will be more likely be for the paid for ones - but it's generally up to the user to be vigilant when clicking on the Next or Install button, although in some cases you get them anyway.

Viruses are a different matter and while no AV is 100% effective, some are better at it than others at stopping drive-bys and when legit download sites have been hacked.

Don't use it myself but have seen posts where some are happy with Comodo Firewall but have also seen some where it has caused Internet connectivity problems - it may have to be a case of suck it and see.

I am currently using Comodo Premium Free. No connection or other problems, however it has a great many configuration options that most will find confusing, myself included. I think several needed features are disabled by default but I am still wanting to research that. The interface is confusing at first (and maybe second ) I believe it is possible to upload configurations that others have perfected. It's on my ever expanding list to do...........